Telephone-exchange line switch



July E0, i923.

H. F. DQBBIN TELEPHONE EXCHANGE LINE SWITCH 2 Sheets-Sheet l Filed Aug. 24, i920 y /M Ven/W4 July 10, 1923.`

H. F. DOBBIN TELEPHONE EXCHANGE umma SWITCH 2 Sheets-Sheet 2 Filed Aug. 24, 1920 Pfg. 2;

@om QQQQ P U L @w z Z Patented July 10, 1923.

SITES ,aria

HENRY F. DOBBIN, OF NEW YORK, N. Y.. ASSIGNOR T WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

TELEPHONE-EXCHANGE LINE SWITCH.

Application flied August 24, 1920.

To all whom t may concern:

Be it known that I, HENRY F. DoBnIN, a citizen of the United States, residing at New York, in the county of New York and State of New York, have invented certain new and useful Improvements in Telephone-EX- change Line Switches. of which the following is a full, clear, concise, and eXact description.

This invention relates, in general, to electric switches and more particularly to switches adapted for use in automatic telephone exchanges. 'Specifically it relates to line switches of the non-numerical type, by means of which a plurality of trunks and a plurality of subscribers lines are so associated that any subscribers line can be automatically connected to any trunk, means being provided whereby idle trunks are individually pre-selected for extension of calls from the subscribers lines to other switches which operate to further extend the connectors to called subscribers lines.

The object of this invention is the provision of a line switch comprising a'veryl simple and economical structure which is readily accessible for repairs and replacements and which for a given number of lines accommodated occupies a minimum amount of space.

One outstanding feature of this invention resides in the employment of a flat type terminal bank consisting of flat metal punchings with Contact terminals projecting laterally from both sides of the bank, the punchings being arranged in superposed relation and insulated one from the other. This type of bank. being accessible to the subscribers linesfrom both sides, makes. possible a material reduction in the volume of space required for the bank. as compared to other line switches heretofore developed.

Another feature resides in the means employed for transmitting the motion of a rotating shaft to a contact brush whereby thel shaft is free to rotate independently of the brush when the latter is engaged with one of the bank terminals and restrained from further movement. The means referred to comprise a pair of flat springs mounted one on each side of the shaft` resiliently engaging the brush. A locking device is employed which operates to restrain the brush from further rotation when the latter is engaged with one of the bank terminals. When.

Serial No. 405,626.

the brush is thus restrained further rotation of the shaft is permitted by virtue of the flexibility of the springs.

The preferred embodiment of this invention will now be described with reference to the drawings, in which Fig. 1 is a partial plan view of the switch; F ig. 2 is a sectional view taken along the line 2 2 of Fig. 1; Fig. 3 is a sectional view taken along the line 33 of Fig. 1; Fig. 4l is a perspective view of a portion of one of the brush shafts showing a pair of U--shaped coupling springs and a brush rig and Fig. 5 is a partial side view of the bank with a section through one set of contact brushes illustrating the relation between the bank terminals and the movable Contact brushes. v

Mounted on the supporting frame 1 is a terminal bank 2 comprising a plurality of fiat punched terminal strips 3, each provided with a plurality of contact terminals projecting laterally from each side. The terminal strips are insulated one from the other by insulators 4. Journaled in the bearings 5, one on each side of the terminal bank, are brush shafts 6, and in the bearings 7 at one end of the switch is a. driving shaft 8 on which are mounted two cams 9, each arranged to engage one of the lever' arms 10 on the brush shafts 6. Also securely mounted on the driving shaft 8 is a ratchet wheel 11, which is operatively associated with the stepping pawl 12 and armature 13 of the motor magnet 14e. Operation of the motor magnet causes the ratchet wheel 11, driving shaft 8, and cams' 9 to rotate unidirectionally and the lever arms 10 being engaged by the cams 9 are caused to reciprocate through a definite angle.

0n the brush shaft 6 are loosely mounted a plurality of brush rigs 19 on each of which are insulatively mounted a set of contact brushes 15, 16, 17 and 18. Pivotally mounted on each of the brush rigs 19 are members 20, provided with insulated pins 21 for engaging and flexing their respective Contact. springs 1 5, 16, 17 and 18, to force the latter into contact with their respective bank terminals, and a rearwardly extending arm 22 arranged to be engaged and operated bythe armature 23 and its associated electromagnet 24. Secured to the brush shafts 6 but insulated therefrom are a number of pairs of U shaped springs 25 provided with normally closed contacts 26. The contact brush rigs are each provided with a pin 27 of insulating material which engage their associated springs 26. Eachpivoted member 20 is pi'ovided with a pin 28 for engaging the aper- V tures 29 in the holding' plate 30.

Normally, the Contact brushes 15, 16, 1T and 18, are out of contact with their respective bank teiminals and the pin 28'is likewise out o'l engagement with the apertures 29 ot the holdingy platev-EO. The contact brushes in normal position together with "the brushrigs 19 and the pivoted members 2O are, therefore, rotatable with their respective brush shai't 6 by virtue o'l:l the enri5 gagement of the springs 25 with the pins 2T.

There isalso associated with each electromagnet 24 a second armature 31 which is arranged to engage, upon operation, its asso- ,ciated contact springs 32 and 34 and move the latter out of contact with the contact f springs 33 and 35, thus cutting off the line 7 relay (not shown) in the usual well-known fmanner.

' i' Rotatably mounted on one ot the brush '25 shafts'6 and insulated Vtherefrom is a trunk selecting brush 36, and associated,therewith is a'stationary commutator 37 comprising a number of individual terminals 33, each ot i which is associated with one oi' the trunks H terminating in the switch, llvlheu the brush shafts 6 are reciprocated forward and back, the vcontact rbrush 36 is moved successively over the terminals 38 and the arrangement vof the circuit with which the switch is asso- `aci ciated is suchl that the motor magnet 14 will remain energized and keep the shaft 3l rotating and tlie'shatt 6 reciprocating, so llong asthe contact brush 36 remains in couta'c't with a terminal 38, which is associated 4,40 with a busy trunk. The means by which this is accomplished is well-known in the art and is believed to require no description here.

As before stated every set of idle contact brushes 15, 16, 1i' and 1S moves with its respective brush shailt 6 so that all the sets ofi'idle brushes are continuously positioned in opera-ble relation to, but out ot contact with, terminals associated with idle trunks. vl"Upon initiation of a call on any subscribers line, thefelectromagnct 24 associated therewith is energized and'its armatures 23 rand 31 ai'e pulled up. Armature 23, in operating, rotates its associated pivoted member 20'so as' to engage pin 28 with one ot the vapertures 29 in holding plate 30 and also to effect engagement i' between the contact brushes a-ndtheiterminals of the idle trunks Vbefore vwhich they were positioned. The contact' brushes are thereupon restrained 90 from"further rotation with their respective t, y ffnet the pin 27.4 remains stationary while 4the switch "is intended to be connected in series with the contacts 26, and the fact that these contacts are only closed when their associated brushes are in normal position, provides a sate guard against the possibility et a subscriber 'being connected to a busy trunk.

At the con'ipletion ot a call the electro` magnet 24 is deenergized and its armatures released, whereupon the pin 23 withdrawn trom the holding plate 30, and the contact springs with their associated parts, are moved, by the tension ol" springs 25, to apositioii in line with the other idle sets ot contact brushes; that is, into operable relation with the then selected idle trunk.

The employment of a flat type terminal bank, having Contact terminals projecting 'from both sides thereoit, makes practicable the arrangement illustrated, wherein the subsci'ibersilines have access to both sides o the bank, thus eti'ecting a. very materiai economykin the space required tor a given number of lines accommodated and incidentally, in the cost ot production oll the switch.

TWhat is claimed is:

1. vln a switch, a stationary contact, a moveable contact member oper-ably associ-v ated with said stationary contact, means toi" moving' said contact member relative to said stationary Contact, means operable to restrain said contact member troni movement relative to said stationary contact, and means?.

conjointly associated with said tiret mentioned means and said contact member where-- by said contact member when not restrained moved simultaneously with said first mentioned means and whereby when said con-- tact member is restrained said tioned means can be moved infilependently tlieicoi".

2. In a switch, a stationary contact. a moveable contact member operably associated with said stationary contact. means Ytor movingsaid contact member relative to said stationary contact, means operable to restrain said contact member from movement relative to said stationary contact,'and flexible4 means conjointly associatedl with said .tirstmeiitionezl means and said contactinembei1 whereby said contact member when not restrained is moved simultaneously with said First mentioned means and whereby when said Contact member is restrained said `tirst mentioned means can be moved `independ- `cn tly thereof.

` 3. In a switch, a stationary contact, a moveable contact member operably associated `withsaid stationary contact, arshatt, means for rotating said shaft, a spring conjointly associatedI with said shaft `and said contact member wherebysaid contact member can .be moved, relativelyy to saidstationtirst menstrain said contact member from further movement when said contact member is engaged l with said stationary Contact, and

vmeans conjointly associated with said first mentioned means and said contact member whereby said first mentioned means and said contact member can be moved simultaneously when said contact member is not restrained and whereby said first mentioned mea/ns can move independently of `said contact member when the latter is restrained.

5. In an automatic switch, the combination with a contact bank having a plurality of sets of contact terminals, of a rotatableA shaft, a set of brushes carried by said shaft and arranged to be moved thereby through progressive positions before said several sets of contact terminals, an electro-magnet ar ranged when energized to bring said brushes intolcontact with the terminals before which they are temporarily positioned, and locking means for said brushes effective during the energization of said electromagnet to prevent the displacement of said brushes by the further rotation of said shaft.

6. In an automatic switch` the combination with a contact bank having a plurality of sets of contact terminals, of a rotatable shaft, a plurality of sets of brushes carried by said shaft and arranged to be moved thereby through progressive positions before their respective sets of contact terminals, an electromagnet individual to each set of brushes and arranged when energized to bring said brushes into contact with the terminals before which they are temporarily positioned, locking means for said brushes effective during the energization of said electromagnet to prevent displacement of the brushes by the further advance of said shaft, and means acting upon the deenergization of said electromagnet to bring said brushes into alignment with the advanced position of said shaft.

7. In a switch, a stationary contact, a ro tatable contact member operably associated with said stationary contact and normally out of contact therewith, a shaft for rotating said contact member, means for rotating said shaft, means operable to effect engagement between said contact member and said stationary contact, means operable to restrain said contact member from rotation when said contact member is not restrainedv and whereby said shaft can move independently7 of said contact member when the latter is restrained.

8. In a switch, a plurality of stationary contacts, a rotatable contact member asso ciated with said stationary contacts and normally out of contact therewith, a shaft for rotating said contact member into operable non-contacting relation to any of said stationary contacts individually, means operable to effect engagement between said Contact member and any of said stationary contacts with which it may be momentarily associated, means for restraining said contact member from rotation when engaged with any of said stationary contacts, and flexible means conjointly associated with said contact member and said shaft whereby said contact member and said shaft can be rotated simultaneously when said Contact member is not restrained and whereby said shaft can be rotated independently of said contact member when the latter is restrained.

9. In a telephone exchange, a terminal bank comprising a plurality of sets of trunk terminals, a trunk for each set of terminals, a movable Contact member associated with and adapted to engage any of said ysets of terminals individually, said contact member being normally out of engagement with said terminals, a line connected to said contact member, means for moving said contact member to bring the latter into operable relation with said sets of terminals, individually, means operable to effect engagement between said contact member and said sets of terminals, individually, means for restraining said contact member from movement relative to said terminals when engaged therewith, means con] ointly associated with said first mentioned means and said contact member whereby said Contact member can be moved simultaneously with said rst mentioned means when said contact member is not restrained and whereby said first mentioned means can be moved independently of said contact member when the latter is restrained, and means for selecting idle trunks.

10. In a. telephone exchange, a terminal bank comprising a plurality of groups of contact terminals, each group comprising a plurality of sets of terminals, a plurality of trunks, each connected in multiple to a set of terminals in each group, a plurality of group of terminals, each conta-ct member beingadapted to engage individually each set `of terminals in its respective group, a plurality oflines, one for each contact member, a rotatable shaft, means for rotating said shaft, means operable to effect engagement between said contact members and their respectively associated sets of contact terminals, individually, means operable to restrain said contact members from moving relative to their respective sets of contact terminals when said contact members are engaged. with any of their respective sets of contacts, means conjointly associated with said contact members and said shaft whereby said contact members when not restrained can be moved by said shaft and whereby said shaft can move independently of said Contact members when the latter ,are restrained, and means for selecting idle trunks.

1l. In a telephone exchange, a terminal bankcomprising a plurality of groups of contact terminals, each group comprising a plurality of sets ofterminals, a plurality of trunks, each connected in multiple to a set of terminals in eachgroup, a plurality of roe tatable contact members, one for each group y ofterminals, each contact member being accessible to each set of terminals inits respective group individually, a plurality of lines, one for each contact member, a rotatable shaft, means for rotating said shaft forward and back through a definite angle, a plurality of spring members, one for. each contact member, each conjointly associated with said shaft and said Contact member and adapted to transmit the motion of said shaft to said contactmember and also adapted to permit said shaft torotate independently of said .contact member when the `latter is re strained from movement, an electromagnet, means for operating said electromagnet, an

,armature operable by said electromagnet to effect engagement between said contact member and any of its respective sets of contact terminals, a retaining device adapted to engage said contact member and prevent its further rotation when said contactmmember is engaged with any of its respective sets of contact terminals, and means for selecting idle trunks.

l2. A line switch comprising a fia-t type terminal bank, a plurality of groups of contact terminals projecting laterally from said bank on both sides thereof, each group comprising a plurality of sets of terminals, a plurality of Contact members, one for each group of terminals, each Contact member being adapted for movement into operable relation with each of its sets of contact members individually, said contact members situated a part on one side and a part on the opposite side of said bank, two shafts sitn uated on opposite sides of said bank and arranged parallel thereto, a plurality of flexibie members, each conj ointly associated with one of said shafts and one of said contact members and adapted to transmit the motion of said shaft to said contact member when said contact member is not restrained, and adapted to permit rotation of said shaft when said contact member is restrained, means for effecting engagement between said contact members `and their respective sets of terminals individually, means for restraining said contact members from vfurther movement when they are engaged with their respective terminals,l

a driving shaft arranged transversely to said first mentioned shafts and adapted for unidirectional rotation, means conjointly associated with said driving shaft and said first mentioned shafts whereby the unidirectional rotation ofsaid driving shaft is converted to reciprocatory rotation of therst mentioned shafts, means for rotating said driving shaft, a plurality of trunks, each connected multiply toone set in each group of terminals, a plurality of lines, one for each contact member, and means'for selecting idle trunks.

In witness whereof, I hereunto subscribe my name this 13th day of August A. D., 1920.

HENRY F. DOBBIN. 

